1. Field
Example embodiments relate to a method of manufacturing a semiconductor light-emitting device. Other example embodiments relate to a method of manufacturing a nitride-based semiconductor light-emitting device having increased efficiency and increased output properties using a comparatively simple and easy process.
2. Description of the Related Art
Among light-emitting devices using a compound semiconductor, for example, a study on the development of nitride (GaN, AlN and/or InN) semiconductor-based light-emitting devices has proceeded. Many light-emitting products, e.g., light emitting diodes (LED), laser diodes (LD) and/or back light units (BLU), for a flat panel display have been developed and are commercially used.
Because the demand for a product with increased brightness using an improved optical efficiency property has rapidly increased, the development of a product with increased brightness, to which an increased current may be applied, may be required. A representative is a light-emitting device for illumination. Because an increased current is needed in a nitride light-emitting device which has increased brightness, an increased amount of heat may be generated during the operation of the device. Generation of heat is the main factor for reducing the life span of the device. The development of a thermostable light-emitting device may need to be solved to develop a light-emitting device with increased brightness for illumination.
Most light-emitting devices using a nitride semiconductor may be manufactured by growing a nitride thin film on a sapphire substrate. The sapphire substrate remains with the nitride thin film continuously after the light-emitting device has been manufactured. Because the remaining sapphire substrate has a lower thermal conductivity than that of the nitride semiconductor, heat generated, when the nitride light-emitting device operates, may not be sufficiently dissipated. The temperature of the nitride thin film that constitutes the light-emitting device may be increased, reducing the life span and efficiency of the light-emitting device. The best solution for heat dissipation caused by the decreased thermal conductivity of the sapphire substrate is to remove the sapphire substrate after the nitride light-emitting device is manufactured.
The most used method is laser lift-off (LLO). In this method, a nitride may be separated at an interface between the sapphire substrate and the nitride thin film by irradiating the laser, thereby removing the sapphire substrate from the nitride thin film. The sapphire substrate may be removed using a LLO process. Due to the increased heat generated in the LLO process, the nitride thin film may be damaged. This damage is the main factor for lowering a light property of the nitride thin film and is an inevitable disadvantage in the LLO process.
To perform the LLO process, the nitride thin film may be fixed using an epoxy. In this procedure, if the nitride thin film is not completely adhered to the epoxy, a crack may occur in the nitride thin film during the LLO process of the sapphire substrate. The crack may cause a decrease in the yield of a product and there may be many difficulties in using the product commercially.